RESPIRATION Flashcards
What is respiration?
the process through which ATP is produced to be used in metabolic pathways
What are the 4 stages of respiration?
glycolysis
the link reaction
the krebs cycle
oxidative phosphorylation
What is required for glycolysis?
Glucose , ATP and NAD
Describe glycolysis:
occurs in the cytoplasm
-Glucose is PHOPHORYLATED
- Rearranged into FRUCTOSE
- Fructose is PHOSPHORYLATED
-HEXOSE (1,6) BIPHOSPHATE
-HB —> TRIOSE PHOSPHATE
-Triose phosphate is oxidised (loses H+)
-NAD becomes NADH
-2 ATP produced
what is the product of glycolysis
4 ATP (2 net gain)
2 NADH
2 pyruvate
what happens after glycolysis and pyruvate production in aerobic respiration ?
Pyruvate entes the LINK REACTION
Define DEHYDROGENATION
removal of Hydrogen atoms
Define DECARBOXYLATION
removal of carbon atoms
Describe the Link reaction :
*occurs in the mithocondria
- pyruvate {3C} is oxided (dehydrogenation) + decarboxylated
-NAD –> NADH
-ACETATE {2C} is produced
-Acetate + Coenzyme A
-Acetylcoenzyme A is produced
how many link reactions per glucose?
2
products of link reaction per glucose
2 AcetylCoA
2 CO2
2 NADH
ingredients of link reaction
2 pyruvate
2 NAD
2 CoA
what is the product that enters the krebs cycle?
acetate
Describe the Krebs cycle:
acetylCoA –> CoA released back into the link reaction to continue to process
- acetate {2C} + OXALOACETATE {4C} = citrate {6C}
- dehydrogenation (NADH )and decarboxylation (CO2)
- 5C molecule
-dehydrogenation and decarboxylation
-4C
-ATP production
-4C
-FADH2 production
-OXALOACETATE (4C)
-dehydrogenation (NADH)
Kreb cycle products :
per turn?
per glucose?
3NADH 6NADH
1 FADH2 2 FADH2
1 ATP 2 ATP
2 CO2 4 CO2
What happens after kreb cycle?
oxidative phosphorylation
main structures and components of oxidative phosphorylation :
NADH
FADH
H+
Oxygen
electrons
electron transfer chain
ATP synthase
first step of oxidative phoshorylation
oxidation of NADH and FADH2
Describe oxidative phosphorylation:
- NADH and FADH2 are oxidized –> NAD and FAD
- Release of H ions
- H ions split into e- and protons+
- H protons concentration increases in the
intermembrane space of mitochondria
- H ions are then pumped in the ATP synthase AGAINST CONCENTRATION GRADIENT.
-H ions goes through atp synthase to allow the functionin of it (get ADP and P together = ATP)
- H in the matrix bind with O2 and electrons to produce H2O
-O2 is the terminal electron acceptor - electrons travel through the electron transport chain (high energy holder protein to low energy holder protein)
- as electron passes through the proteins it looses energy
- protein go through OXIDATION-REDUCTION process
- last protein –> electrons released into the matrix
what is the electrochemical gradient
the difference of H+ ions concentration across two membranes, the concentration of H+ is greater in the intermembrane space compared to the matrix
what is the function of H+?
to allow the functioning of ATP synthase
what happens to H+ after being pumped through the ATP synthase?
binds with electrons and oxygen to produce H2O
pumped in the intermembrane space again.
what is the electron donor
NADH and FADH2 since they release H+
what in an electron acceptor
oxygen
describe chemiosmosis
process by which the movement of H+ IONS across a semipermeable membrane generates ATP
what is anaerobic respiration
respiration in absence of oxygen
anaerobic respiration in animals
Glucose –> Pyruvate –> Lactate
while pyruvate is produced NAD is reduced and become NADH.
to allow the NADH to be reused in glycolysis , pyruvate accept 2 H+ ions (reduced) and becomes Lactate, NAD can be regenerated
process can be reversed as no atoms are lost and lactase dehydrogenase is available to reverse reaction, and small ATP is still used
reason for anaerobic respiration
since there is no oxygen , ETC cannot function since it doesnt have the terminal electron acceptor (oxygen) , if the ETC cannot function there is an accumulation of NADH AND FADH2
anaerobic respiration in yeast cells
pyruvate –> decarboxylation –> ethanal –> ethanal reduced –> ethanol
cannot be reversed as atoms are lost
decarboxylase enzyme cannot reverse
what are the differences between ANR in animals and yeast cells.
animals dont have an intermediate molecule however yeast cells do (ethanal)
animals cells do not go through decarboxylation whereas yeast cell do
in animal cell pyruvate is reduced wheras in yeast cells ethanal is reduced
what are other substrates that can be used for respiration
carbohydrates
lipids
proteins
Phosphocreatine
A phosphate source in muscle cells
ATP that doesnt involve electron transport chain
substrate-level phosphorylation
how is ATP produced in the Krebs cycle
ADP+P
substrate level phosphorylation
enzyme catalysed reaction
“explain how the rate of respiration can be calculated from the graph and their observation”
- rate is inversely proportional to the time taken for colour change , 1: time
- respiration is directly proportional to the rate of colour change
“advantage of respiring both anaerobically and aerobically”
-despite no oxygen is viable, glycolysis can still continue
- to produce small amount of ATP
